Virginity & periods

So I lost my virginity two months ago. Before that, my periods lasted 8 - 10 days and were extremely heavy 4 out of 8 days, 5 if it was a 10 day period. Since I lost my virginity my periods have changed, they lasted 5 days these last two months and only had heavy bleeding one day, and the others it's extremely light. I was wondering if this has happened to anyone else and what is the reason for it?